int pow(int a, int b)
{
    int result = a;
    while (b != 1)
    {
        result *= a;
        b--;
    }
    return result;
}

unsigned long long int createInterestingNum(int n)
{
    if (n == 1)
        return n;

    unsigned long long int num = createInterestingNum(n - 1);
    int multiplFactor = pow(10, pow(2, n - 1));

    return  num * multiplFactor + n * (multiplFactor / 10) + num;
}